Ferromagnetic tunnel magnetoresistive devices and magnetic head

ABSTRACT

The present invention provides a ferromagnetic tunnel magnetoresistive film which is associated with a high output and whose magnetoresistive ratio is less dependent on a bias voltage.  
     In a three-terminal ferromagnetic tunnel magnetoresistive element, a decrease in an output is suppressed by a bias voltage V 1 , applied to one of the tunnel junctions. By employing half-metallic ferromagnets  11  and  12  in the element, the output can be enhanced and the dependency on the applied bias voltage can be reduced.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a ferromagnetic tunnelmagnetoresistive element and a magnetic head using the same.

[0003] 2. Description of Related Prior Art

[0004] Conventionally, ferromagnetic tunnel magnetoresistive (TMR)elements have been proposed as one type of magnetoresistive elements.JP-A-10-4227 describes a magnetic head using a TMR element. However, themagnetoresistance of such a conventional TMR element depends greatly onan applied voltage where a TMR ratio becomes lower as a voltage isapplied. In order to employ the TMR element in a magnetic head or amagnetic memory, it is necessary to increase the output while decreasingthe dependency thereof on the applied voltage. An increase in the outputcan be achieved by applying a half-metallic ferromagnet whose degree ofspin-polarization is higher than that of a magnetic ferromagnet used inthe conventional TMR element. An attempt to increase a TMR ratio in aTMR element using a material associated with a high degree ofspin-polarization (La_(0.7)Sr_(0.3)MnO₃/SrTiO₃/La_(0.7)Sr_(0.3)MnO₃) isdescribed in Europhysics Letters, 39(5), pp. 545-549 (1997). PhysicalReview Letters describes that 40% to 50% TMR ratio can be obtained up toan applied voltage of about 1 V in Co/SrTiO₃/La_(0.7)Sr_(0.3)MnO₃.

SUMMARY OF THE INVENTION

[0005] There has been no solution to the decrease in the TMR ratio aswell as its dependency on an applied bias voltage. Thus, the presentinvention has an objective of providing a ferromagnetic tunnelmagnetoresistive element whose output is higher and whosemagnetoresistive ratio is less dependent on an applied bias voltagecompared to conventional elements. In addition, the present inventionhas an objective of providing a magnetoresistive magnetic head and amagnetic memory device using such a ferromagnetic tunnelmagnetoresistive element.

[0006] The degree of spin-polarization (P) of electrons is generallyunderstood as a difference between the numbers (densities of states) ofelectrons in different rotation directions (about their own axes) (wherea clockwise spin is referred to as a downward spin and an anticlockwisespin as an upward spin). For example, the degree of spin-polarizationP=0.8 indicates that the number of upward spins is nine times higherthan that of downward spins.

[0007] A half-metallic ferromagnet is a completely polarized ferromagnethaving a gap of densities of states of upward and downward 3d electronicspins of about 1 eV. Fermi energy (E_(F)) is present across either oneof the densities of state. Since electrons in charge of electronictransport exist at around the Fermi energy, only one of the spins willhave a transport property. Thus, the degree of spin-polarization (P) ina half-metallic ferromagnet is 1. On the other hand, ferromagneticmetals such as Co (Co-based alloy), Fe (Fe-based alloy) and Ni (Ni-basedalloy) have a degree of polarization of about 0.4, with no gap in the 3dband, and with both upward and downward spins present at Fermi energy.

[0008] The magnetoresistance (TMR ratio) of a TMR element may berepresented as 2P₁P₂/(1−P₁P₂) using the above-mentioned degree ofspin-polarization P, where P₁ and P₂ are degrees of spin-polarization oftwo respective ferromagnetic layers sandwiching an insulating barrierlayer of the TMR element. In order to obtain a high TMR ratio, ahalf-metallic ferromagnet with a high degree of spin-polarization P(Fe₃O₄, CrO₂, etc.) is advantageously used.

[0009] The dependency of the TMR element on an applied bias voltage isknown to depend on profiles of the densities of states at interfaces ofthe two ferromagnetic layers with the insulating barrier layer, withinthe barrier height. Accordingly, a desirable bias voltage dependency ofa TMR ratio can be obtained by appropriately combining the insulatingbarrier layer with the ferromagnetic layers of the TMR element.

[0010] Basically, the present invention has a three-terminal structureincluding upper ferromagnetic layer/insulating barrierlayer/intermediate ferromagnetic layer/insulating barrier layer/lowerferromagnetic layer, each ferromagnetic layer having an electrodeterminal. Two electric closed-circuits (for example, a closed-circuitbetween the upper ferromagnetic layer and the lower ferromagnetic layer,and a closed-circuit between the intermediate ferromagnetic layer andthe lower ferromagnetic layer) are provided to vary the bias voltageapplied to the tunnel element in one of the closed-circuits, therebydecreasing the bias voltage dependency of a magnetoresistive ratio inthe other closed-circuit.

[0011] Specifically, the objective of the present invention can beachieved with the following ferromagnetic tunnel magnetoresistiveelements.

[0012] (1) A ferromagnetic tunnel magnetoresistive element, comprising:a first ferromagnetic layer; a first insulating barrier layer formed onthe first ferromagnetic layer; a second ferromagnetic layer formed onthe first insulating barrier layer; a second insulating barrier layerformed on the second ferromagnetic layer; and a third ferromagneticlayer formed on the second insulating barrier layer, wherein the elementfurther comprises a terminal for applying a first bias voltage betweenthe first ferromagnetic layer and the third ferromagnetic layer, and aterminal for applying a second bias voltage between the secondferromagnetic layer and the first or third ferromagnetic layer.

[0013] (2) A ferromagnetic tunnel magnetoresistive element according to(1), further comprising a first antiferromagnetic layer under the firstferromagnetic layer for fixing the magnetization direction of the firstferromagnetic layer, and a second antiferromagnetic layer on the thirdferromagnetic layer for fixing the magnetization direction of the thirdferromagnetic layer.

[0014] (3) A ferromagnetic tunnel magnetoresistive element according toeither one of (1) and (2), wherein the second ferromagnetic layer isformed of a lamination of three ferromagnetic metal layers.

[0015] (4) A ferromagnetic tunnel magnetoresistive element according to(1), wherein each of the first and second ferromagnetic layers is formedof a lamination of two ferromagnetic metal layers.

[0016] (5) A ferromagnetic tunnel magnetoresistive element according toany one of (1) to (4), wherein at least one of the first, second andthird ferromagnetic layers makes contact with a non-magnetic metallayer.

[0017] The objective of the present invention can also be achieved withthe following magnetic head.

[0018] (6) A magnetic head provided with a magnetoresistive elementcomprising: a first ferromagnetic layer; a first insulating barrierlayer formed on the first ferromagnetic layer; a second ferromagneticlayer formed on the first insulating barrier layer; a second insulatingbarrier layer formed on the second ferromagnetic layer; and a thirdferromagnetic layer formed on the second insulating barrier layer,wherein the element further comprises a terminal for applying a firstbias voltage between the first ferromagnetic layer and the thirdferromagnetic layer, and a terminal for applying a second bias voltagebetween the second ferromagnetic layer and the first or thirdferromagnetic layer.

[0019] (7) A magnetic head according to (6), wherein the element furthercomprises a first antiferromagnetic layer under the first ferromagneticlayer for fixing the magnetization direction of the first ferromagneticlayer, and a second antiferromagnetic layer on the third ferromagneticlayer for fixing the magnetization direction of the third ferromagneticlayer.

[0020] (8) A magnetic head according to either one of (6) and (7),wherein the second ferromagnetic layer is formed of a lamination ofthree ferromagnetic metal layers.

[0021] (9) A magnetic head according to (6), wherein each of the firstand second ferromagnetic layers is formed of a lamination of twoferromagnetic metal layers.

[0022] (10) A magnetic head according to any one of (6) to (9), whereinat least one of the first, second and third ferromagnetic layers makescontact with a non-magnetic metal layer.

[0023] Furthermore, the objective of the present invention can beachieved with the following ferromagnetic tunnel magnetoresistiveelement.

[0024] (11) A ferromagnetic tunnel magnetoresistive element, comprising:a first half-metallic ferromagnetic layer; a first insulating barrierlayer formed on the first half-metallic ferromagnetic layer; aferromagnetic metal layer formed on the first insulating barrier layer;a second insulating barrier layer formed on the ferromagnetic metallayer; and a second half-metallic ferromagnetic layer formed on thesecond insulating barrier layer, wherein the element further comprises aterminal for applying a first bias voltage between the firsthalf-metallic ferromagnetic layer and the second half-metallicferromagnetic layer, and a terminal for applying a second bias voltagebetween the ferromagnetic metal layer and the first or secondhalf-metallic ferromagnetic layer.

[0025] (12) A ferromagnetic tunnel magnetoresistive element according to(11), further comprising a first antiferromagnetic layer under the firsthalf-metallic ferromagnetic layer for fixing the magnetization directionof the first half-metallic ferromagnetic layer, and a secondantiferromagnetic layer on the second half-metallic ferromagnetic layerfor fixing the magnetization direction of the second half-metallicferromagnetic layer.

[0026] (13) A ferromagnetic tunnel magnetoresistive element according toeither one of (11) and (12), wherein the ferromagnetic metal layer isformed of a lamination of three ferromagnetic metal layers.

[0027] (14) A ferromagnetic tunnel magnetoresistive element, comprising:a first ferromagnetic metal layer; a first insulating barrier layerformed on the first ferromagnetic metal layer; a half-metallicferromagnetic layer formed on the first insulating barrier layer; asecond insulating barrier layer formed on the half-metallicferromagnetic layer; and a second ferromagnetic metal layer formed onthe second insulating barrier layer, wherein the element furthercomprises a terminal for applying a first bias voltage between the firstferromagnetic metal layer and the second ferromagnetic metal layer, anda terminal for applying a second bias voltage between the half-metallicferromagnetic layer and the first or second ferromagnetic metal layer.

[0028] (15) A ferromagnetic tunnel magnetoresistive element according to(14), wherein each of the first and second ferromagnetic metal layershas a lamination of two ferromagnetic metal layers.

[0029] (16) A ferromagnetic tunnel magnetoresistive element according to(14), further comprising a first antiferromagnetic layer under the firstferromagnetic metal layer for fixing the magnetization direction of thefirst ferromagnetic metal layer, and a second antiferromagnetic layer onthe second ferromagnetic metal layer for fixing the magnetizationdirection of the second ferromagnetic metal layer.

[0030] (17) A ferromagnetic tunnel magnetoresistive element according toany one of (11) to (16), wherein the half-metallic ferromagnetic layeris an oxide or a compound comprising Fe, Co or Mn.

[0031] (18) A ferromagnetic tunnel magnetoresistive element, comprising:a first antiferromagnetic layer; a half-metallic ferromagnetic layerformed on the first antiferromagnetic layer; a first insulating barrierlayer formed on the first half-metallic ferromagnetic layer; a firstferromagnetic metal layer formed on the first insulating barrier layer;a second insulating barrier layer formed on the first ferromagneticmetal layer; a second ferromagnetic metal layer formed on the secondinsulating barrier layer; and a second antiferromagnetic layer formed onthe second ferromagnetic metal layer, wherein the element furthercomprises a terminal for applying a first bias voltage between thehalf-metallic ferromagnetic layer and the second ferromagnetic metallayer, and a terminal for applying a second bias voltage between thefirst ferromagnetic metal layer and the half-metallic ferromagneticlayer or the second ferromagnetic metal layer.

[0032] (19) A ferromagnetic tunnel magnetoresistive element according to(18), wherein the first ferromagnetic metal layer is formed of alamination of three ferromagnetic metal layers.

[0033] (20) A ferromagnetic tunnel magnetoresistive element, comprising:a first antiferromagnetic layer; a first ferromagnetic metal layerformed on the first antiferromagnetic layer; a first insulating barrierlayer formed on the first ferromagnetic metal layer; a secondferromagnetic metal layer formed on the first insulating barrier layer;a second insulating barrier layer formed on the second ferromagneticmetal layer; a third ferromagnetic metal layer formed on the secondinsulating barrier layer; and a second antiferromagnetic layer formed onthe third ferromagnetic metal layer, wherein the element furthercomprises a terminal for applying a first bias voltage between the firstferromagnetic metal layer and the third ferromagnetic metal layer, and aterminal for applying a second bias voltage between the secondferromagnetic metal layer and the first or third ferromagnetic metallayer.

[0034] (21) A ferromagnetic tunnel magnetoresistive element according toany one of (11) to (20), wherein each of the first and second insulatingbarrier layers is made of an oxide or a compound comprising at least oneof Al, Mg, Ti, Ta, Hf, Nb, Mo, Cr, Ga and As.

[0035] The objective of the present invention can also be achieved withthe following magnetic head.

[0036] (22) A magnetic head provided with a magnetoresistive elementcomprising: a first half-metallic ferromagnetic layer; a firstinsulating barrier layer formed on the first half-metallic ferromagneticlayer; a ferromagnetic metal layer formed on the first insulatingbarrier layer; a second insulating barrier layer formed on theferromagnetic metal layer; and a second half-metallic ferromagneticlayer formed on the second insulating barrier layer, wherein the elementfurther comprises a terminal for applying a first bias voltage betweenthe first and second half-metallic ferromagnetic layers, and a terminalfor applying a second bias voltage between the ferromagnetic metal layerand the first or second half-metallic ferromagnetic layer.

[0037] (23) A magnetic head according to (22), wherein the elementfurther comprises a first antiferromagnetic layer under the firsthalf-metallic ferromagnetic layer for fixing the magnetization directionof the first half-metallic ferromagnetic layer, and a secondantiferromagnetic layer on the second half-metallic ferromagnetic layerfor fixing the magnetization direction of the second half-metallicferromagnetic layer.

[0038] (24) A magnetic head according to either one of (22) and (23),wherein the ferromagnetic metal layer is formed of a lamination of threeferromagnetic metal layers.

[0039] (25) A magnetic head provided with a magnetoresistive elementcomprising: a first ferromagnetic metal layer; a first insulatingbarrier layer formed on the first ferromagnetic metal layer; ahalf-metallic ferromagnetic layer formed on the first insulating barrierlayer; a second insulating barrier layer formed on the half-metallicferromagnetic layer; and a second ferromagnetic layer formed on thesecond insulating barrier layer, wherein the element further comprises aterminal for applying a first bias voltage between the firstferromagnetic metal layer and the second ferromagnetic metal layer, anda terminal for applying a second bias voltage between the half-metallicferromagnetic layer and the first or second ferromagnetic metal layer.

[0040] (26) A magnetic head according to (25), wherein each of the firstand second ferromagnetic metal layers is formed of a lamination of twoferromagnetic metal layers.

[0041] (27) A magnetic head according to (25), wherein the elementfurther comprises a first antiferromagnetic layer under the firstferromagnetic metal layer for fixing the magnetization direction of thefirst ferromagnetic metal layer, and a second antiferromagnetic layer onthe second ferromagnetic metal layer for fixing the magnetizationdirection of the second ferromagnetic metal layer.

[0042] (28) A magnetic head according to any one of (22) to (27),wherein the half-metallic ferromagnetic layer is an oxide or a compoundcomprising Fe, Co or Mn.

[0043] (29) A magnetic head provided with a magnetoresistive elementcomprising: a first antiferromagnetic layer; a half-metallicferromagnetic layer formed on the first antiferromagnetic layer; a firstinsulating barrier layer formed on the first half-metallic ferromagneticlayer; a first ferromagnetic metal layer formed on the first insulatingbarrier layer; a second insulating barrier layer formed on the firstferromagnetic metal layer; a second ferromagnetic metal layer formed onthe second insulating barrier layer; and a second antiferromagneticlayer formed on the second ferromagnetic metal layer, wherein theelement further comprises a terminal for applying a first bias voltagebetween the half-metallic ferromagnetic layer and the secondferromagnetic metal layer, and a terminal for applying a second biasvoltage between the first ferromagnetic metal layer and thehalf-metallic ferromagnetic layer or the second ferromagnetic metallayer.

[0044] (30) A magnetic head according to (29), wherein the firstferromagnetic metal layer is formed of a lamination of threeferromagnetic metal layers.

[0045] (31) A magnetic head provided with a magnetoresistive elementcomprising: a first antiferromagnetic layer; a first ferromagnetic metallayer formed on the first antiferromagnetic layer; a first insulatingbarrier layer formed on the first ferromagnetic metal layer; a secondferromagnetic metal layer formed on the first insulating barrier layer;a second insulating barrier layer formed on the second ferromagneticmetal layer; a third ferromagnetic metal layer formed on the secondinsulating barrier layer; and a second antiferromagnetic layer formed onthe third ferromagnetic metal layer, wherein the element furthercomprises a terminal for applying a first bias voltage between the firstferromagnetic metal layer and the third ferromagnetic metal layer, and aterminal for applying a second bias voltage between the secondferromagnetic metal layer and the first or third ferromagnetic metallayer.

[0046] (32) A magnetic head according to any one of (22) to (31),wherein each of the first and second insulating barrier layers is madeof an oxide or a compound comprising at least one of Al, Mg, Ti, Ta, Hf,Nb, Mo, Cr, Ga and As.

[0047] In using the ferromagnetic tunnel magnetoresistive element, acurrent is provided in a thickness direction of the layers.

[0048] Moreover, the ferromagnetic tunnel magnetoresistive element ispreferably formed on an alignment film. Examples of the alignment filminclude an oxide or a compound containing at least one of Ni, Zr, Zn,Al, Mg, Ti, Ta, Hf, Nb, Mo, Cr and Co.

BRIEF DESCRIPTION OF THE DRAWINGS

[0049]FIG. 1 is a schematic cross-sectional view showing one example ofa three-terminal ferromagnetic tunnel element of the present invention;

[0050]FIGS. 2A and 2B are graphs where FIG. 2A shows a V₁ dependency ofa magnetoresistive ratio of the three-terminal ferromagnetic tunnelelement shown in FIG. 1 where V₂=0, while FIG. 2B shows a V₂ dependencyof a magnetoresistive ratio of the three-terminal ferromagnetic tunnelelement shown in FIG. 1 where V₁=V₁′;

[0051]FIG. 3 is a schematic cross-sectional view showing another exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0052]FIG. 4 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0053]FIG. 5 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0054]FIG. 6 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0055]FIG. 7 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0056]FIG. 8 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0057]FIG. 9 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0058]FIG. 10 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0059]FIG. 11 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0060]FIG. 12 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0061]FIG. 13 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0062]FIG. 14 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0063]FIG. 15 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0064]FIG. 16 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0065]FIG. 17 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0066]FIG. 18 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0067]FIGS. 19A and 19B are graphs where FIG. 19A shows a V₁ dependencyof a magnetoresistive ratio of the three-terminal ferromagnetic tunnelelement shown in FIG. 18 where V₂=0, while FIG. 19B shows a V₂dependency of a magnetoresistive ratio of the three-terminalferromagnetic tunnel element shown in FIG. 18 where V₁=V₁′;

[0068]FIG. 20 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0069]FIG. 21 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0070]FIG. 22 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0071]FIG. 23 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0072]FIG. 24 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0073]FIG. 25 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0074]FIG. 26 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0075]FIG. 27 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0076]FIG. 28 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0077]FIG. 29 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0078]FIG. 30 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0079]FIG. 31 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0080]FIG. 32 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0081]FIG. 33 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0082]FIG. 34 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0083]FIG. 35 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0084]FIGS. 36A and 36B are graphs where FIG. 36A shows a V₁ dependencyof a magnetoresistive ratio of the three-terminal ferromagnetic tunnelelement shown in FIG. 35 where V₂=0, while FIG. 36B shows a V₂dependency of a magnetoresistive ratio of the three-terminalferromagnetic tunnel element shown in FIG. 35 where V₁=V₁′;

[0085]FIG. 37 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0086]FIG. 38 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0087]FIG. 39 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0088]FIG. 40 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0089]FIG. 41 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0090]FIG. 42 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0091]FIG. 43 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0092]FIG. 44 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0093]FIG. 45 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0094]FIG. 46 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0095]FIG. 47 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0096]FIG. 48 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0097]FIG. 49 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0098]FIG. 50 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0099]FIG. 51 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0100]FIG. 52 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0101]FIG. 53 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0102]FIG. 54 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0103]FIG. 55 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0104]FIG. 56 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0105]FIG. 57 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0106]FIG. 58 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0107]FIG. 59 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0108]FIG. 60 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0109]FIG. 61 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0110]FIG. 62 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0111]FIG. 63 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0112]FIG. 64 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0113]FIG. 65 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0114]FIG. 66 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0115]FIG. 67 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0116]FIG. 68 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0117]FIG. 69 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0118]FIG. 70 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0119]FIG. 71 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0120]FIG. 72 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0121]FIG. 73 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0122]FIG. 74 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0123]FIG. 75 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0124]FIG. 76 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0125]FIG. 77 is a schematic cross- sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0126]FIG. 78 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0127]FIG. 79 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0128]FIG. 80 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0129]FIG. 81 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0130]FIG. 82 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0131]FIG. 83 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0132]FIG. 84 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0133]FIG. 85 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0134]FIG. 86 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0135]FIG. 87 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0136]FIG. 88 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0137]FIG. 89 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0138]FIG. 90 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0139]FIG. 91 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0140]FIG. 92 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0141]FIG. 93 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0142]FIG. 94 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0143]FIG. 95 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0144]FIG. 96 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0145]FIG. 97 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0146]FIG. 98 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0147]FIG. 99 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0148]FIG. 100 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0149]FIGS. 101A and 101B are graphs where FIG. 101A shows a V₁dependency of a magnetoresistive ratio of the three-terminalferromagnetic tunnel element shown in FIG. 100 where V₂=0, while FIG.101B shows a V₂ dependency of a magnetoresistive ratio of thethree-terminal ferromagnetic tunnel element shown in FIG. 100 whereV₁=V₁′;

[0150]FIG. 102 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0151]FIG. 103 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0152]FIG. 104 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0153]FIG. 105 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0154]FIG. 106 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0155]FIG. 107 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0156]FIG. 108 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0157]FIG. 109 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0158]FIG. 110 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0159]FIG. 111 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0160]FIG. 112 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0161]FIG. 113 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0162]FIG. 114 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0163]FIG. 115 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0164]FIG. 116 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0165]FIG. 117 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0166]FIG. 118 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0167]FIG. 119 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0168]FIG. 120 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0169]FIG. 121 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0170]FIG. 122 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0171]FIG. 123 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0172]FIG. 124 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0173]FIG. 125 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0174]FIG. 126 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0175]FIG. 127 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0176]FIG. 128 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0177]FIG. 129 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0178]FIG. 130 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0179]FIG. 131 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0180]FIG. 132 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0181]FIG. 133 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0182]FIG. 134 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0183]FIG. 135 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0184]FIG. 136 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0185]FIG. 137 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0186]FIG. 138 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0187]FIG. 139 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0188]FIG. 140 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0189]FIG. 141 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0190]FIG. 142 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0191]FIG. 143 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0192]FIG. 144 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0193]FIG. 145 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0194]FIG. 146 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0195]FIG. 147 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0196]FIG. 148 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0197]FIG. 149 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0198]FIG. 150 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0199]FIG. 151 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0200]FIG. 152 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0201]FIG. 153 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0202]FIG. 154 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0203]FIG. 155 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0204]FIG. 156 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0205]FIG. 157 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0206]FIG. 158 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0207]FIG. 159 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0208]FIG. 160 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0209]FIG. 161 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0210]FIG. 162 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0211]FIG. 163 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0212]FIG. 164 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0213]FIG. 165 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0214]FIG. 166 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0215]FIG. 167 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0216]FIG. 168 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0217]FIG. 169 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0218]FIG. 170 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0219]FIG. 171 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0220]FIG. 172 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0221]FIG. 173 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0222]FIG. 174 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0223]FIG. 175 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0224]FIG. 176 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0225]FIG. 177 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0226]FIG. 178 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0227]FIG. 179 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0228]FIG. 180 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0229]FIG. 181 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0230]FIG. 182 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0231]FIG. 183 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0232]FIG. 184 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0233]FIG. 185 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0234]FIG. 186 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0235]FIG. 187 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0236]FIG. 188 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0237]FIG. 189 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0238]FIG. 190 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0239]FIG. 191 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0240]FIG. 192 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0241]FIG. 193 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0242]FIG. 194 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0243]FIG. 195 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0244]FIG. 196 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0245]FIG. 197 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0246]FIG. 198 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0247]FIG. 199 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0248]FIG. 200 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0249]FIG. 201 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0250]FIG. 202 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0251]FIG. 203 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0252]FIG. 204 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0253]FIG. 205 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0254]FIG. 206 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0255]FIG. 207 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0256]FIG. 208 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0257]FIG. 209 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0258]FIG. 210 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0259]FIG. 211 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0260]FIG. 212 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0261]FIG. 213 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0262]FIG. 214 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0263]FIG. 215 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0264]FIG. 216 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0265]FIG. 217 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0266]FIG. 218 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0267]FIG. 219 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0268]FIG. 220 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0269]FIG. 221 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0270]FIG. 222 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0271]FIG. 223 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0272]FIG. 224 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0273]FIG. 225 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0274]FIG. 226 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0275]FIG. 227 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0276]FIG. 228 is a schematic cross-sectional view showing other exampleof a three-terminal ferromagnetic tunnel element of the invention;

[0277]FIG. 229 is a schematic perspective view showing a read/write headusing a three-terminal ferromagnetic tunnel element of the invention;and

[0278]FIG. 230 is a schematic view showing an exemplary structure of amagnetic writing device provided with the read/write head using thethree-terminal ferromagnetic tunnel element of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0279] Hereinafter, embodiments of the present invention will bedescribed with reference to the accompanying drawings.

EMBODIMENT 1

[0280] FIGS. 1 to 17 are schematic cross-sectional views showingexamples of a three-terminal ferromagnetic tunnel element (hereinafter,referred to as a “three-terminal TMR element”) of the invention. Thethree-terminal TMR elements shown in FIGS. 1 to 17 each have a basicstructure of a half-metallic ferromagnetic layer, an insulating barrierlayer, a ferromagnetic metal layer, an insulating barrier layer and ahalf-metallic ferromagnetic layer laminated in this order on asubstrate.

[0281]FIG. 1 is a schematic cross-sectional view showing one example ofthe three-terminal ferromagnetic tunnel element of the invention. Thisthree-terminal TMR element includes an antiferromagnetic layer 32 (30nm), a half-metallic ferromagnetic layer 12 (30 nm), an insulatingbarrier layer 22 (2 nm), a ferromagnetic metal layer 41 (10 nm), aninsulating barrier layer 21 (2 nm), a half-metallic ferromagnetic layer11 (30 nm) and an antiferromagnetic layer 31 (30 nm) laminated in thisorder on a substrate. An electrode terminal is formed in each of thehalf-metallic ferromagnetic layers 11 and 12 to form an electricclosed-circuit between the layers 11 and 12 (a bias voltage applied bythis closed-circuit is defined as V₁) while an electrode terminal isformed in each of the ferromagnetic metal layer 41 and the half-metallicferromagnetic layer 12 to form an electric closed-circuit between thelayers 41 and 12 (a bias voltage applied by this closed-circuit isdefined as V₂). This element was produced by sputtering or depositiontechnique, and photolithography.

[0282] Arrows in the figure represent directions of currents provided tothe element, which may be vice versa as long as the relativerelationship of the directions remains the same. Specifically, when thedirection of a current of the bias voltage V₁ is reversed with respectto the arrow in FIG. 1, the direction of the current of the bias voltageV₂ should also be reversed. The V₂ circuit may be formed between thehalf-metallic ferromagnetic layer 11 and the ferromagnetic metal layer41.

[0283] Hereinafter, materials used for the respective layers of theabove-described three-terminal TMR element will be described. Thehalf-metallic ferromagnetic layers 11 and 12 are made from half-metallicferromagnets with a very high degree of spin-polarization includingFe₃O₄, CrO₂, La_(0.7)Sr_(0.3)MnO₃, Sr₂FeMoO₆ and Mn compounds such asMnSb. The insulating barrier layers 21 and 22 are made of SrTiO₃, butthey may also be made of MgO, HfO₂, TaO, NbO, MoO, TiO₂ or Al₂O₃. Theferromagnetic metal layer 41 is made of CoFe alloy, but it may also bemade of Co or NiFe. The antiferromagnetic layers 31 and 32 are made ofNiO.

[0284]FIG. 2A shows an applied bias voltage V₁ dependency of the TMRratio of the three-terminal TMR element shown in FIG. 1 under V₂=0. FIG.2B shows an applied bias voltage V₂ dependency of the TMR ratio of thethree-terminal TMR element shown in FIG. 1 under V₁=V₁′. Here, V₁′ is avalue of the applied bias voltage V₁ where the highest TMR ratio isobtained in FIG. 2A. According to the present example, the bias voltagedependency of the magnetoresistive ratio between the half-metallicferromagnetic layers 11 and 12 is such that the TMR ratio becomes thehighest at about ±0.25 V and decreases at a bias voltage higher thanthat. By setting V₁ to V₁′ and by varying the bias voltage V₂ appliedbetween the ferromagnetic metal layer 41 and the half-metallicferromagnetic layer 12, the magnetoresistive ratio can be doubled with anegative bias voltage, thereby reducing the bias voltage dependency.

[0285]FIG. 3 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.1 except that the ferromagnetic metal layer 41 is replaced with atri-layered film made from ferromagnetic metal layers 411, 412 and 413.This structure eases the magnetization rotation of the ferromagneticmetal layers 411, 412 and 413. In each of the following examplesdescribed with respect to FIGS. 5, 9 to 11, and 15 to 17, theferromagnetic metal layer 41 is made from three layers for the samereason. The ferromagnetic metal layers 411 and 413 are made of aCo-based alloy (CoFe), and the ferromagnetic metal layer 412 is made ofa Ni-based alloy (NiFe). The element of the present example had the sameTMR characteristics as those shown in FIGS. 2A and 2B.

[0286]FIG. 4 is a schematic cross-sectional view showing other exemplarythree-terminal TMR element of the invention. This three-terminal TMRelement has the same structure as that shown in FIG. 1 without theantiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 2A and 2B. In this example, asoft magnetic half-metallic ferromagnetic layer can be applied. In thefollowing examples described with respect to FIGS. 5, and 12 to 17, theantiferromagnetic layers are not provided adjacent to the half-metallicferromagnetic layers for this reason.

[0287]FIG. 5 is a schematic cross-sectional view showing other exemplarythree-terminal TMR element of the invention. This three-terminal TMRelement has the same structure as that shown in FIG. 3 without theantiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 2A and 2B.

[0288]FIG. 6 is a schematic cross-sectional view showing other exemplarythree-terminal TMR element of the invention. This three-terminal TMRelement has the same structure as that shown in FIG. 1 except that anon-magnetic metal layer 51 is formed between the insulating barrierlayer 21 and the ferromagnetic metal layer 41. The non-magnetic metallayer 51 may be selected from Au, Cu, Cr, Zn, Ga, Nb, Mo, Ru, Pd, Ag,Hf, Ta, W, Pt and Bi. The element had the same TMR characteristics asthose shown in FIGS. 2A and 2B. By arranging the non-magnetic metallayer adjacent to the ferromagnetic metal layer, the density of statesof the bulk of the ferromagnetic metal layer will contribute toconductance, by which the bias voltage dependency of the TMR ratio canbe improved. In the following examples described with respect to FIGS. 7to 17, non-magnetic metal layers are used for the same reason.

[0289]FIG. 7 is a schematic cross-sectional view showing other exemplarythree-terminal TMR element of the invention. This three-terminal TMRelement has the same structure as that shown in FIG. 6 except that anon-magnetic metal layer 51 is formed between the insulating barrierlayer 22 and the ferromagnetic metal layer 41. The element had the sameTMR characteristics as those shown in FIGS. 2A and 2B.

[0290]FIG. 8 is a schematic cross-sectional view showing other exemplarythree-terminal TMR element of the invention. This three-terminal TMRelement has the same structure as that shown in FIG. 1 except that anon-magnetic metal layer 51 is formed between the insulating barrierlayer 21 and the ferromagnetic metal layer 41, and a non-magnetic metallayer 52 is formed between the insulating barrier layer 22 and theferromagnetic metal layer 41. Similar to the non-magnetic metal layer51, the non-magnetic metal layer 52 may be selected from Au, Cu, Cr, Zn,Ga, Nb, Mo, Ru, Pd, Ag, Hf, Ta, W, Pt and Bi. The element had the sameTMR characteristics as those shown in FIGS. 2A and 2B.

[0291]FIG. 9 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.6 except that the ferromagnetic metal layer 41 is replaced with atri-layered film made from ferromagnetic metal layers 411, 412 and 413.The ferromagnetic metal layers 411 and 413 are made of a Co-based alloy(CoFe), and the ferromagnetic metal layer 412 is made of a Ni-basedalloy (NiFe). The element of the present example had the same TMRcharacteristics as those shown in FIGS. 2A and 2B.

[0292]FIG. 10 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.7 except that the ferromagnetic metal layer 41 is replaced with atri-layered film made from ferromagnetic metal layers 411, 412 and 413.The ferromagnetic metal layers 411 and 413 are made of a Co-based alloy(CoFe), and the ferromagnetic metal layer 412 is made of a Ni-basedalloy (NiFe). The element of the present example had the same TMRcharacteristics as those shown in FIGS. 2A and 2B.

[0293]FIG. 11 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.8 except that the ferromagnetic metal layer 41 is replaced with atri-layered film made from ferromagnetic metal layers 411, 412 and 413.The ferromagnetic metal layers 411 and 413 are made of a Co-based alloy(CoFe), and the ferromagnetic metal layer 412 is made of a Ni-basedalloy (NiFe). The element of the present example had the same TMRcharacteristics as those shown in FIGS. 2A and 2B.

[0294]FIG. 12 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.6 without the antiferromagnetic layers 31 and 32. The element had thesame TMR characteristics as those shown in FIGS. 2A and 2B.

[0295]FIG. 13 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.7 without the antiferromagnetic layers 31 and 32. The element had thesame TMR characteristics as those shown in FIGS. 2A and 2B.

[0296]FIG. 14 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.8 without the antiferromagnetic layers 31 and 32. The element had thesame TMR characteristics as those shown in FIGS. 2A and 2B.

[0297]FIG. 15 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.9 without the antiferromagnetic layers 31 and 32. The element had thesame TMR characteristics as those shown in FIGS. 2A and 2B.

[0298]FIG. 16 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.10 without the antiferromagnetic layers 31 and 32. The element had thesame TMR characteristics as those shown in FIGS. 2A and 2B.

[0299]FIG. 17 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thisthree-terminal TMR element has the same structure as that shown in FIG.11 without the antiferromagnetic layers 31 and 32. The element had thesame TMR characteristics as those shown in FIGS. 2A and 2B.

[0300] In the examples shown in FIGS. 3 to 17, the bias voltage V₂ maybe applied between the half-metallic ferromagnetic layer 11 and theferromagnetic metal layer 41 (412).

EMBODIMENT 2

[0301] In the examples shown in FIGS. 18 to 34, each of thethree-terminal TMR elements has a basic structure where a ferromagneticmetal layer, an insulating barrier layer, a half-metallic ferromagneticlayer, an insulating barrier layer and a ferromagnetic metal layer arelaminated on a substrate in this order.

[0302]FIG. 18 is a schematic cross-sectional view showing other exampleof the three-terminal ferromagnetic tunnel element of the invention. Thethree-terminal TMR element of this example includes an antiferromagneticlayer 32 (30 nm), a ferromagnetic metal layer 42 (5 nm), an insulatingbarrier layer 22 (2 nm), a half-metallic ferromagnetic layer 11 (30 nm),an insulating barrier layer 21 (2 nm), a ferromagnetic metal layer 41 (5nm), and an antiferromagnetic layer 31 (30 nm) laminated in this orderon a substrate. An electrode terminal is formed in each of theferromagnetic metal layers 41 and 42 to form an electric closed-circuitbetween the layers 41 and 42 (a bias voltage applied by thisclosed-circuit is defined as V₁) while an electrode terminal is formedin each of the ferromagnetic metal layer 42 and the half-metallicferromagnetic layer 11 to form an electric closed-circuit between thelayers 42 and 11 (a bias voltage applied by this closed-circuit isdefined as V₂). This element was produced by sputtering or depositiontechnique, and photolithography.

[0303] Arrows in the figure represent directions of currents provided tothe element, which may be vice versa as long as the relativerelationship of the directions remains the same. Specifically, when thedirection of a current of the bias voltage V₁ is reversed with respectto the arrow in FIG. 18, the direction of the current of the biasvoltage V₂ should also be reversed. In this example, the bias voltage V₂may be applied between the half-metallic ferromagnetic layer 11 and theferromagnetic metal layer 41.

[0304] Hereinafter, materials used for the respective layers of theabove-described three-terminal TMR element will be described. Thehalf-metallic ferromagnetic layer 11 is made from a half-metallicferromagnet with very high degree of spin-polarization including Fe₃O₄,CrO₂, La_(0.7)Sr_(0.3)MnO₃, Sr₂FeMoO₆ and Mn compounds such as MnSb. Theinsulating barrier layers 21 and 22 are made of SrTiO₃, but they mayalso be made of MgO, HfO₂, TaO, NbO, MoO, TiO₂ or Al₂O₃. Theferromagnetic metal layers 41 and 42 are made of CoFe alloy, but theymay also be made of Co or NiFe. The antiferromagnetic layers 31 and 32are made of PtMn.

[0305]FIG. 19A shows an applied bias voltage V₁ dependency of the TMRratio of the three-terminal TMR element shown in FIG. 18 under V₂=0.FIG. 19B shows an applied bias voltage V₂ dependency of the TMR ratio ofthe three-terminal TMR element shown in FIG. 18 under V₁=V₁′. Here, V₁′is a value of the bias voltage V₁ where the highest TMR ratio isobtained in FIG. 19A. The three-terminal TMR element of this example hasthe same effect as that described with reference to FIGS. 2A and 2Bexcept that the increase in the magnetoresistive ratio and well biasvoltage dependency is obtained with a positive bias voltage due to thearrangement of the material as the ferromagnetic layer.

[0306]FIG. 20 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 18 except that a non-magnetic metal layer 51 isformed between the ferromagnetic metal layer 41 and the insulatingbarrier layer 21. The non-magnetic metal layer 51 is selected from Au,Cu, Cr, Zn, Ga, Nb, Mo, Ru, Pd, Ag, Hf, Ta, W, Pt and Bi. The elementhad the same TMR characteristics as those shown in FIGS. 19A and 19B. Byarranging the non-magnetic metal layer adjacent to the ferromagneticmetal layer, the effects described with reference to FIG. 6 can berealized. In the following examples described with respect to FIGS. 22to 34, non-magnetic metal layers are arranged adjacent to ferromagneticmetal layers for the same reason.

[0307]FIG. 21 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 20 except that a non-magnetic metal layer 51 isformed between the ferromagnetic metal layer 42 and the insulatingbarrier layer 22. The element had the same TMR characteristics as thoseshown in FIGS. 19A and 19B.

[0308]FIG. 22 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 18 except that a non-magnetic metal layer 51 isformed between the ferromagnetic metal layer 41 and the insulatingbarrier layer 21, and a non-magnetic metal layer 52 is formed betweenthe ferromagnetic metal layer 41 and the insulating barrier layer 22.Similar to the non-magnetic metal layer 51, the non-magnetic metal layer52 may be selected from Au, Cu, Cr, Zn, Ga, Nb, Mo, Ru, Pd, Ag, Hf, Ta,W, Pt and Bi. The element had the same TMR characteristics as thoseshown in FIGS. 19A and 19B.

[0309]FIG. 23 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 18 except that the ferromagnetic metal layer 41 isreplaced with a tri-layered film made from a ferromagnetic metal layer414, a non-magnetic metal layer 53 and a ferromagnetic metal layer 415,and the ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 421, a non-magnetic metal layer 54and a ferromagnetic metal layer 422. This structure eases themagnetization rotation of the half-metallic ferromagnetic layer 11. Inthe following examples, the ferromagnetic metal layer 41 is alsoreplaced with the tri-layered film for the same reason. Theferromagnetic metal layers 414, 415, 421 and 422 are made of a Co-basedalloy. The non-magnetic metal layers 53 and 54 are made of either Ru orCu. The element of the present example had the same TMR characteristicsas those shown in FIGS. 19A and 19B.

[0310]FIG. 24 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 20 except that the ferromagnetic metal layer 41 isreplaced with a tri-layered film made from a ferromagnetic metal layer414, a non-magnetic metal layer 53 and a ferromagnetic metal layer 415,and the ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 421, a non-magnetic metal layer 54and a ferromagnetic metal layer 422. The ferromagnetic metal layers 414,415, 421 and 422 are made of a Co-based alloy. The non-magnetic metallayers 53 and 54 are made of either Ru or Cu. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 19A and19B.

[0311]FIG. 25 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 21 except that the ferromagnetic metal layer 41 isreplaced with a tri-layered film made from a ferromagnetic metal layer414, a non-magnetic metal layer 53 and a ferromagnetic metal layer 415,and the ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 421, a non-magnetic metal layer 54and a ferromagnetic metal layer 422. The ferromagnetic metal layers 414,415, 421 and 422 are made of a Co-based alloy. The non-magnetic metallayers 53 and 54 may be made of either Ru or Cu. The element of thepresent example had the same TMR characteristics as those shown in FIGS.19A and 19B.

[0312]FIG. 26 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 22 except that the ferromagnetic metal layer 41 isreplaced with a tri-layered film made from a ferromagnetic metal layer414, a non-magnetic metal layer 53 and a ferromagnetic metal layer 415,and the ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 421, a non-magnetic metal layer 54and a ferromagnetic metal layer 422. The ferromagnetic metal layers 414,415, 421 and 422 are made of a Co-based alloy. The non-magnetic metallayers 53 and 54 may be made of either Ru or Cu. The element of thepresent example had the same TMR characteristics as those shown in FIGS.19A and 19B.

[0313]FIG. 27 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 18 without the antiferromagnetic layers 31 and 32.This structure allows the use of a soft magnetic half-metallicferromagnetic layer. In the following examples, the antiferromagneticlayers are not provided adjacent to the half-metallic ferromagneticlayers for this reason. The element had the same TMR characteristics asthose shown in FIGS. 19A and 19B.

[0314]FIG. 28 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 21 without the antiferromagnetic layers 31 and 32.The element had the same TMR characteristics as those shown in FIGS. 19Aand 19B.

[0315]FIG. 29 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 20 withcut the antiferromagnetic layers 31 and 32.The element had the same TMR characteristics as those shown in FIGS. 19Aand 19B.

[0316]FIG. 30 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 22 without the antiferromagnetic layers 31 and 32.The element had the same TMR characteristics as those shown in FIGS. 19Aand 19B.

[0317]FIG. 31 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 27 except that the ferromagnetic metal layer 41 isreplaced with a double-layered film made from ferromagnetic metal layers411 and 412, and the ferromagnetic metal layer 42 is replaced with adouble-layered film made from ferromagnetic metal layers 421 and 422.Replacing the ferromagnetic metal layers 41 and 42 with thedouble-layered structures eases the magnetization rotation, therebyenhancing magnetization sensitivity of the magnetoresistive ratio. Theelement of the present example had the same TMR characteristics as thoseshown in FIGS. 19A and 19B.

[0318]FIG. 32 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 28 except that the ferromagnetic metal layer 41 isreplaced with a double-layered film made from ferromagnetic metal layers411 and 412, and the ferromagnetic metal layer 42 is replaced with adouble-layered film made from ferromagnetic metal layers 421 and 422.The element of the present example had the same TMR characteristics asthose shown in FIGS. 19A and 19B.

[0319]FIG. 33 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 29 except that the ferromagnetic metal layer 41 isreplaced with a double-layered film made from ferromagnetic metal layers411 and 412, and the ferromagnetic metal layer 42 is replaced with adouble-layered film made from ferromagnetic metal layers 421 and 422.The element of the present example had the same TMR characteristics asthose shown in FIGS. 19A and 19B.

[0320]FIG. 34 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. Thethree-terminal TMR element of this example has the same structure asthat shown in FIG. 30 except that the ferromagnetic metal layer 41 isreplaced with a double-layered film made from ferromagnetic metal layers411 and 412, and the ferromagnetic metal layer 42 is replaced with adouble-layered film made from ferromagnetic metal layers 421 and 422.The element of the present example had the same TMR characteristics asthose shown in FIGS. 19A and 19B. In the structures shown in FIGS. 20 to34, the bias voltage V₂ may be applied between the half-metallicferromagnetic layer 11 and the ferromagnetic metal layer 41 (411, 414).

EMBODIMENT3

[0321] In the examples shown in FIGS. 35 to 99, each of thethree-terminal TMR elements has a basic structure where a ferromagneticmetal layer, an insulating barrier layer, a ferromagnetic metal layer,an insulating barrier layer and a ferromagnetic metal layer arelaminated on a substrate in this order.

[0322]FIG. 35 is a schematic cross-sectional view showing other exampleof the three-terminal ferromagnetic tunnel element of the invention. Thethree-terminal TMR element of this example includes an antiferromagneticlayer 32 (12 nm), a ferromagnetic metal layer 43 (3 nm), an insulatingbarrier layer 22 (1 nm), a ferromagnetic metal layer 42 (5 nm), aninsulating barrier layer 21 (1 nm), a ferromagnetic metal layer 41 (3nm), and an antiferromagnetic layer 31 (12 nm) laminated in this orderon a substrate. An electrode terminal is formed in each of theferromagnetic metal layers 41 and 43 to form an electric closed-circuitbetween the layers 41 and 43 (a bias voltage applied by thisclosed-circuit is defined as V₁) while an electrode terminal is formedin each of the ferromagnetic metal layer 42 and 43 to form an electricclosed-circuit between the layers 42 and 43 (a bias voltage applied bythis closed-circuit is defined as V₂). This element was produced bysputtering or deposition technique, and photolithography. Arrows in thefigure represent directions of currents provided to the element, whichmay be vice versa as long as the relative relationship of the directionsremains the same. In this example, the bias voltage V₂ may be appliedbetween the ferromagnetic metal layers 41 and 42.

[0323] Hereinafter, materials used for the respective layers of theabove-described three-terminal TMR element will be described. Theinsulating barrier layers 21 and 22 are made of SrTiO₃, but they mayalso be made of MgO, HfO₂, TaO, NbO, MoO, TiO₂ or Al₂O₃. Theferromagnetic metal layers 41, 42 and 43 are made of CoFe alloy, butthey may also be made of Co or NiFe. The antiferromagnetic layers 31 and32 are made of PtMn.

[0324]FIG. 36A shows an applied bias voltage V₁ dependency of the TMRratio of the three-terminal TMR element shown in FIG. 35 under V₂=0.FIG. 36B shows an applied bias voltage V₂ dependency of the TMR ratio ofthe three-terminal TMR element shown in FIG. 35 under V₁=V₁′. Here, V₁′is a value of the bias voltage where the highest TMR ratio is obtainedin FIG. 36A. In the present structure, V₁′ is almost 0, but an increasein the magnetoresistive ratio can be realized by varying V₂. With thebias voltage dependency of the present example, a magnetoresistive ratioof 50% can be obtained when the bias voltage V₂ is ±0.5 V.

[0325]FIG. 37 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 41 and the insulating barrier layer 21. By arranging thenon-magnetic metal layer to be adjacent to the ferromagnetic metallayer, the effects described with reference to FIG. 6 can be realized.In the following examples, non-magnetic metal layers are arrangedadjacent to ferromagnetic metal layers for the same reason. Thenon-magnetic metal layer 51 may be selected from Au, Cu, Cr, Zn, Ga, Nb,Mo, Ru, Pd, Ag, Hf, Ta, W, Pt and Bi. The element had the same TMRcharacteristics as those shown in FIGS. 36A and 36B.

[0326]FIG. 38 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 42 and the insulating barrier layer 21. The element had the sameTMR characteristics as those shown in FIGS. 36A and 36B.

[0327]FIG. 39 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 42 and the insulating barrier layer 22. The element had the sameTMR characteristics as those shown in FIGS. 36A and 36B.

[0328]FIG. 40 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 43 and the insulating barrier layer 22. The element had the sameTMR characteristics as those shown in FIGS. 36A and 36B.

[0329]FIG. 41 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 42 and the insulating barrier layer 21, and a non-magnetic metallayer 52 is formed between the ferromagnetic metal layer 42 and theinsulating barrier layer 22. Similar to the non-magnetic metal layer 51,the non-magnetic metal layer 52 may be selected from Au, Cu, Cr, Zn, Ga,Nb, Mo, Ru, Pd, Ag, Hf, Ta, W, Pt and Bi. The element had the same TMRcharacteristics as those shown in FIGS. 36A and 36B.

[0330]FIG. 42 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 41 and the insulating barrier layer 21, and a non-magnetic layer52 is formed between the ferromagnetic metal layer 42 and the insulatingbarrier layer 21. The element had the same TMR characteristics as thoseshown in FIGS. 36A and 36B.

[0331]FIG. 43 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 41 and the insulating barrier layer 21, and a non-magnetic layer52 is formed between the ferromagnetic metal layer 42 and the insulatingbarrier layer 22. The element had the same TMR characteristics as thoseshown in FIGS. 36A and 36B.

[0332]FIG. 44 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 42 and the insulating barrier layer 21, and a non-magnetic layer52 is formed between the ferromagnetic metal layer 43 and the insulatingbarrier layer 22. The element had the same TMR characteristics as thoseshown in FIGS. 36A and 36B.

[0333]FIG. 45 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 42 and the insulating barrier layer 22, and a non-magnetic layer52 is formed between the ferromagnetic metal layer 43 and the insulatingbarrier layer 22. The element had the same TMR characteristics as thoseshown in FIGS. 36A and 36B.

[0334]FIG. 46 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 41 and the insulating barrier layer 21, and a non-magnetic layer52 is formed between the ferromagnetic metal layer 43 and the insulatingbarrier layer 22. The element had the same TMR characteristics as thoseshown in FIGS. 36A and 36B.

[0335]FIG. 47 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 41 and the insulating barrier layer 21, a non-magnetic layer 52 isformed between the ferromagnetic metal layer 42 and the insulatingbarrier layer 21, and a non-magnetic metal layer 55 is formed betweenthe ferromagnetic metal layer 42 and the insulating barrier layer 22.The element had the same TMR characteristics as those shown in FIGS. 36Aand 36B.

[0336]FIG. 48 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 41 and the insulating barrier layer 21, a non-magnetic layer 52 isformed between the ferromagnetic metal layer 42 and the insulatingbarrier layer 21, and a non-magnetic metal layer 55 is formed betweenthe ferromagnetic metal layer 43 and the insulating barrier layer 22.The element had the same TMR characteristics as those shown in FIGS. 36Aand 36B.

[0337]FIG. 49 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 42 and the insulating barrier layer 21, a non-magnetic layer 52 isformed between the ferromagnetic metal layer 42 and the insulatingbarrier layer 22, and a non-magnetic metal layer 55 is formed betweenthe ferromagnetic metal layer 43 and the insulating barrier layer 22.The element had the same TMR characteristics as those shown in FIGS. 36Aand 36B.

[0338]FIG. 50 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 41 and the insulating barrier layer 21, a non-magnetic layer 52 isformed between the ferromagnetic metal layer 42 and the insulatingbarrier layer 22, and a non-magnetic metal layer 55 is formed betweenthe ferromagnetic metal layer 43 and the insulating barrier layer 22.The element had the same TMR characteristics as those shown in FIGS. 36Aand 36B.

[0339]FIG. 51 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thata non-magnetic metal layer 51 is formed between the ferromagnetic metallayer 41 and the insulating barrier layer 21, a non-magnetic layer 52 isformed between the ferromagnetic metal layer 42 and the insulatingbarrier layer 21, a non-magnetic metal layer 55 is formed between theferromagnetic metal layer 42 and the insulating barrier layer 22, and anon-magnetic metal layer 56 is formed between the ferromagnetic metallayer 43 and the insulating barrier layer 22. The element had the sameTMR characteristics as those shown in FIGS. 36A and 36B.

[0340]FIG. 52 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. This structureeases the magnetization rotation of the ferromagnetic metal layers 423,424 and 425. In the following examples, the ferromagnetic metal layer 42is also replaced with the tri-layered film for the same reason. Theferromagnetic metal layers 423 and 425 are made of a Co-based alloywhile the ferromagnetic metal layer 424 is made of a Ni-based alloy. Theelement of the present example had the same TMR characteristics as thoseshown in FIGS. 36A and 36B.

[0341]FIG. 53 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 37 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0342]FIG. 54 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 38 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0343]FIG. 55 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 39 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0344]FIG. 56 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 40 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0345]FIG. 57 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 41 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0346]FIG. 58 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 42 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0347]FIG. 59 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 43 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0348]FIG. 60 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 44 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0349]FIG. 61 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 45 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0350]FIG. 62 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 46 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0351]FIG. 63 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 47 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0352]FIG. 64 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 48 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0353]FIG. 65 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 49 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0354]FIG. 66 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 50 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0355]FIG. 67 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 51 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0356]FIG. 68 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 35 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The ferromagnetic metal layers 414, 415, 431 and 432 are made of aCo-based alloy. The non-magnetic metal layers 53 and 54 are made ofeither Ru or Cu. The element of the present example had the same TMRcharacteristics as those shown in FIGS. 36A and 36B.

[0357]FIG. 69 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 37 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0358]FIG. 70 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 38 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0359]FIG. 71 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 39 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0360]FIG. 72 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 40 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0361]FIG. 73 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 41 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0362]FIG. 74 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 42 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0363]FIG. 75 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 43 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0364]FIG. 76 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 44 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0365]FIG. 77 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 45 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0366]FIG. 78 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 46 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0367]FIG. 79 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 47 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0368]FIG. 80 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 48 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0369]FIG. 81 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 49 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0370]FIG. 82 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 50 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0371]FIG. 83 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 51 except thatthe ferromagnetic metal layer 41 is replaced with a tri-layered filmmade from a ferromagnetic metal layer 414, a non-magnetic metal layer 53and a ferromagnetic metal layer 415, and the ferromagnetic metal layer43 is replaced with a tri-layered film made from a ferromagnetic metallayer 431, a non-magnetic metal layer 54 and a ferromagnetic metal layer432. The element of the present example had the same TMR characteristicsas those shown in FIGS. 36A and 36B.

[0372]FIG. 84 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 68 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0373]FIG. 85 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 69 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0374]FIG. 86 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 70 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0375]FIG. 87 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 71 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0376]FIG. 88 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 72 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0377]FIG. 89 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 73 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0378]FIG. 90 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 74 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0379]FIG. 91 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 75 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0380]FIG. 92 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 76 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0381]FIG. 93 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 77 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0382]FIG. 94 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 78 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0383]FIG. 95 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 79 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0384]FIG. 96 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 80 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0385]FIG. 97 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 81 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0386]FIG. 98 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 82 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B.

[0387]FIG. 99 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 83 except thatthe ferromagnetic metal layer 42 is replaced with a tri-layered filmmade from ferromagnetic metal layers 423, 424 and 425. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 36A and 36B. In the examples shown in FIGS. 37 to 99, the biasvoltage V₂ may be applied between the ferromagnetic metal layers 41(414) and 42 (424).

EMBODIMENT 4

[0388] In the examples shown in FIGS. 100 to 228, each of thethree-terminal TMR elements has a basic structure where a half-metallicferromagnetic layer, an insulating barrier layer, a ferromagnetic metallayer, an insulating barrier layer and a ferromagnetic metal layer arelaminated on a substrate in this order.

[0389]FIG. 100 is a schematic cross-sectional view showing other exampleof the three-terminal ferromagnetic tunnel element of the invention. Thethree-terminal TMR element of this example includes an antiferromagneticlayer 32 (30 nm), a half-metallic ferromagnetic layer 11 (30 nm), aninsulating barrier layer 22 (2 nm), a ferromagnetic metal layer 42 (10nm), an insulating barrier layer 21 (1 nm), a ferromagnetic metal layer41 (5 nm), and an antiferromagnetic layer 31 (12 nm) laminated in thisorder on a substrate. An electrode terminal is formed in each of thehalf-metallic ferromagnetic layer 11 and the ferromagnetic metal layer41 to form an electric closed-circuit between the layers 11 and 41 (abias voltage applied by this closed-circuit is defined as V₁) while anelectrode terminal is formed in each of the half-metallic ferromagneticlayer 11 and the ferromagnetic metal layer 42 to form an electricclosed-circuit between the layers 11 and 42 (a bias voltage applied bythis closed-circuit is defined as V₂). This element was produced bysputtering or deposition technique, and photolithography. Arrows in thefigure represent directions of currents provided to the element, whichmay be vice versa as long as the relative relationship of the directionsremains the same. In this example, the bias voltage V₂ may be appliedbetween the ferromagnetic metal layers 41 and 42.

[0390] Hereinafter, materials used for the respective layers of theabove-described three-terminal TMR element will be described. Theinsulating barrier layers 21 and 22 are made of SrTiO₃, but they mayalso be made of MgO, HfO₂, TaO, NbO, MoO, TiO₂ or Al₂O₃. Theferromagnetic metal layers 41 and 42 are made of CoFe alloy, but theymay also be made of Co or NiFe. The half-metallic ferromagnetic layer 11is made from a half-metallic ferromagnet with a very high degree ofspin-polarization including Fe₃O₄, CrO₂, La_(0.7)Sr_(0.3)MnO₃, Sr₂FeMoO₆and Mn compounds such as MnSb. The antiferromagnetic layer 32 is made ofNiO.

[0391]FIG. 101A shows an applied bias voltage V₁ dependency of the TMRratio of the three-terminal TMR element shown in FIG. 100 under V₂=0.FIG. 101B shows an applied bias voltage V₂ dependency of the TMR ratioof the three-terminal TMR element under V₁=V₁′. Here, V₁′ is a value ofthe bias voltage where the highest TMR ratio is obtained in FIG. 101A.This example also has the same effect as that described with referenceto FIGS. 2A and 2B. Although the increase in the magnetoresistive ratiois significant at about 0 V due to the arrangement of the material asthe ferromagnetic layer, there is no problem.

[0392]FIG. 102 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 exceptthat a non-magnetic metal layer 51 is formed between the ferromagneticmetal layer 41 and the insulating barrier layer 21. By arranging thenon-magnetic metal layer to be adjacent to the ferromagnetic metallayer, the effects described with reference to FIG. 6 can be realized.In the following examples, non-magnetic metal layers are arrangedadjacent to ferromagnetic metal layers for the same reason. Thenon-magnetic metal layer 51 may be selected from Au, Cu, Cr, Zn, Ga, Nb,Mo, Ru, Pd, Ag, Hf, Ta, W, Pt and Bi. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0393]FIG. 103 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 exceptthat a non-magnetic metal layer 51 is formed between the ferromagneticmetal layer 42 and the insulating barrier layer 21. The element had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0394]FIG. 104 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 exceptthat a non-magnetic metal layer 51 is formed between the ferromagneticmetal layer 42 and the insulating barrier layer 22. The element had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0395]FIG. 105 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 exceptthat a non-magnetic metal layer 51 is formed between the ferromagneticmetal layer 41 and the insulating barrier layer 21, and a non-magneticmetal layer 52 is formed between the ferromagnetic metal layer 42 andthe insulating barrier layer 21. The non-magnetic metal layers 51 and 52may be selected from Au, Cu, Cr, Zn, Ga, Nb, Mo, Ru, Pd, Ag, Hf, Ta, W,Pt and Bi. The element had the same TMR characteristics as those shownin FIGS. 101A and 101B.

[0396]FIG. 106 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 exceptthat a non-magnetic metal layer 51 is formed between the ferromagneticmetal layer 41 and the insulating barrier layer 21, and a non-magneticmetal layer 52 is formed between the ferromagnetic metal layer 42 andthe insulating barrier layer 22. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0397]FIG. 107 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 exceptthat a non-magnetic metal layer 51 is formed between the ferromagneticmetal layer 42 and the insulating barrier layer 21, and a non-magneticmetal layer 52 is formed between the ferromagnetic metal layer 42 andthe insulating barrier layer 22. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0398]FIG. 108 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 exceptthat a non-magnetic metal layer 51 is formed between the ferromagneticmetal layer 41 and the insulating barrier layer 21, a non-magnetic metallayer 52 is formed between the ferromagnetic metal layer 42 and theinsulating barrier layer 21, and a non-magnetic metal layer 53 is formedbetween the ferromagnetic metal layer 42 and the insulating barrierlayer 22. Similar to the non-magnetic metal layer 51, the non-magneticmetal layer 53 may be any one of Au, Cu, Cr, Zn, Ga, Nb, Mo, Ru, Pd, Ag,Hf, Ta, W, Pt and Bi. The element had the same TMR characteristics asthose shown in FIGS. 101A and 101B.

[0399]FIG. 109 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 exceptthat the ferromagnetic metal layer 42 is replaced with a tri-layeredfilm made from ferromagnetic metal layers 423, 424 and 425. Thisstructure eases the magnetization rotation of the ferromagnetic metallayers 423, 424 and 425. In the following examples, the ferromagneticmetal layer 42 is also replaced with the tri-layered film for the samereason. The ferromagnetic metal layers 423 and 425 are made of aCo-based alloy while the ferromagnetic metal layer 424 is made of aNi-based alloy. The element of the present example had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0400]FIG. 110 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 102 exceptthat the ferromagnetic metal layer 42 is replaced with a tri-layeredfilm made from ferromagnetic metal layers 423, 424 and 425. The elementof the present example had the same TMR characteristics as those shownin FIGS. 101A and 101B.

[0401]FIG. 111 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 103 exceptthat the ferromagnetic metal layer 42 is replaced with a tri-layeredfilm made from ferromagnetic metal layers 423, 424 and 425. The elementof the present example had the same TMR characteristics as those shownin FIGS. 101A and 101B.

[0402]FIG. 112 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 104 exceptthat the ferromagnetic metal layer 42 is replaced with a tri-layeredfilm made from ferromagnetic metal layers 423, 424 and 425. The elementof the present example had the same TMR characteristics as those shownin FIGS. 101A and 101B.

[0403]FIG. 113 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 105 exceptthat the ferromagnetic metal layer 42 is replaced with a tri-layeredfilm made from ferromagnetic metal layers 423, 424 and 425. The elementof the present example had the same TMR characteristics as those shownin FIGS. 101A and 101B.

[0404]FIG. 114 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 106 exceptthat the ferromagnetic metal layer 42 is replaced with a tri-layeredfilm made from ferromagnetic metal layers 423, 424 and 425. The elementof the present example had the same TMR characteristics as those shownin FIGS. 101A and 101B.

[0405]FIG. 115 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 107 exceptthat the ferromagnetic metal layer 42 is replaced with a tri-layeredfilm made from ferromagnetic metal layers 423, 424 and 425. The elementof the present example had the same TMR characteristics as those shownin FIGS. 101A and 101B.

[0406]FIG. 116 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 108 exceptthat the ferromagnetic metal layer 42 is replaced with a tri-layeredfilm made from ferromagnetic metal layers 423, 424 and 425. The elementof the present example had the same TMR characteristics as those shownin FIGS. 101A and 101B.

[0407]FIG. 117 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The ferromagnetic metallayers 414 and 415 are made of a Co-based alloy. The non-magnetic metallayer 53 is made of either Ru or Cu. The element of the present examplehad the same TMR characteristics as those shown in FIGS. 101A and 101B.

[0408]FIG. 118 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 102 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0409]FIG. 119 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 103 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0410]FIG. 120 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 104 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0411]FIG. 121 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 105 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0412]FIG. 122 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 106 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0413]FIG. 123 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 107 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0414]FIG. 124 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 108 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0415]FIG. 125 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 109 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0416]FIG. 126 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 110 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0417]FIG. 127 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 111 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0418]FIG. 128 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 112 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0419]FIG. 129 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 113 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0420]FIG. 130 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 114 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0421]FIG. 131 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 115 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0422]FIG. 132 is a schematic cross-sectional view showing anotherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 116 exceptthat the ferromagnetic metal layer 41 is replaced with a tri-layeredfilm made from a ferromagnetic metal layer 414, a non-magnetic metallayer 53 and a ferromagnetic metal layer 415. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0423]FIG. 133 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B. This structureallows an application of a soft magnetic half-metallic ferromagneticlayer. In some of the following examples, the antiferromagnetic layersare not provided for this reason.

[0424]FIG. 134 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 102 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0425]FIG. 135 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 103 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0426]FIG. 136 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 104 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0427]FIG. 137 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 105 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0428]FIG. 138 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 106 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0429]FIG. 139 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 107 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0430]FIG. 140 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 108 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0431]FIG. 141 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 109 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0432]FIG. 142 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 110 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0433]FIG. 143 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 111 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0434]FIG. 144 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 112 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0435]FIG. 145 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 113 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0436]FIG. 146 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 114 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0437]FIG. 147 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 115 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0438]FIG. 148 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 116 withoutthe antiferromagnetic layers 31 and 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0439]FIG. 149 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 133 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The ferromagneticmetal layer 411 is made of a Co-based alloy while the ferromagneticmetal layer 412 is made of a Ni-based alloy. The element of the presentexample had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0440]FIG. 150 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 134 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0441]FIG. 151 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 135 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0442]FIG. 152 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 136 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0443]FIG. 153 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 137 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0444]FIG. 154 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 138 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0445]FIG. 155 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 139 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0446]FIG. 156 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 140 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0447]FIG. 157 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 141 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0448]FIG. 158 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 142 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0449]FIG. 159 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 143 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0450]FIG. 160 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 144 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0451]FIG. 161 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 145 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0452]FIG. 162 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 146 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0453]FIG. 163 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 147 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0454]FIG. 164 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 148 exceptthat the ferromagnetic metal layer 41 is replaced with a double-layeredfilm made from ferromagnetic metal layers 411 and 412. The element ofthe present example had the same TMR characteristics as those shown inFIGS. 101A and 101B.

[0455]FIG. 165 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 withoutthe antiferromagnetic layer 32. This structure allows an application ofa soft magnetic half-metallic ferromagnetic layer. The element had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0456]FIG. 166 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 102 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0457]FIG. 167 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 103 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0458]FIG. 168 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 104 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0459]FIG. 169 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 105 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0460]FIG. 170 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 106 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0461]FIG. 171 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 107 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0462]FIG. 172 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 108 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0463]FIG. 173 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 109 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0464]FIG. 174 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 110 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0465]FIG. 175 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 111 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0466]FIG. 176 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 112 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0467]FIG. 177 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 113 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0468]FIG. 178 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 114 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0469]FIG. 179 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 115 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0470]FIG. 180 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 116 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0471]FIG. 181 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 117 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0472]FIG. 182 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 118 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0473]FIG. 183 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 119 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0474]FIG. 184 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 120 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0475]FIG. 185 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 121 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0476]FIG. 186 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 122 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0477]FIG. 187 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 123 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0478]FIG. 188 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 124 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0479]FIG. 189 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 125 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0480]FIG. 190 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 126 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0481]FIG. 191 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 127 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0482]FIG. 192 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 128 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0483]FIG. 193 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 129 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0484]FIG. 194 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 130 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0485]FIG. 195 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 131 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0486]FIG. 196 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 132 withoutthe antiferromagnetic layer 32. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0487]FIG. 197 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 100 withoutthe antiferromagnetic layer 31. Removal of the antiferromagnetic layer31 eases magnetization rotation of the ferromagnetic metal layer 41. Theelement had the same TMR characteristics as those shown in FIGS. 101Aand 101B.

[0488]FIG. 198 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 102 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0489]FIG. 199 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 103 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0490]FIG. 200 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 104 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0491]FIG. 201 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 105 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0492]FIG. 202 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 106 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0493]FIG. 203 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 107 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0494]FIG. 204 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 108 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0495]FIG. 205 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 109 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0496]FIG. 206 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 110 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0497]FIG. 207 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 111 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0498]FIG. 208 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 112 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0499]FIG. 209 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 113 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0500]FIG. 210 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 114 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0501]FIG. 211 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 115 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0502]FIG. 212 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. The element ofthis example has the same structure as that shown in FIG. 116 withoutthe antiferromagnetic layer 31. The element had the same TMRcharacteristics as those shown in FIGS. 101A and 101B.

[0503]FIG. 213 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 149 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0504]FIG. 214 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 150 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0505]FIG. 215 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 151 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0506]FIG. 216 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 152 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0507]FIG. 217 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 153 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0508]FIG. 218 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 154 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0509]FIG. 219 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 155 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0510]FIG. 220 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 156 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0511]FIG. 221 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 157 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0512]FIG. 222 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 158 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0513]FIG. 223 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 159 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0514]FIG. 224 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 160 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0515]FIG. 225 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 161 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0516]FIG. 226 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 162 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0517]FIG. 227 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 163 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B.

[0518]FIG. 228 is a schematic cross-sectional view showing otherexemplary three-terminal TMR element of the invention. According to thisexample, the lamination film shown in FIG. 164 is formed on theantiferromagnetic layer 31. The element of the present example had thesame TMR characteristics as those shown in FIGS. 101A and 101B. In theexamples shown in FIGS. 102 to 228, the bias voltage V₂ may be appliedbetween the ferromagnetic metal layers 41 (414) and 42 (424).

[0519]FIG. 229 is a schematic perspective view of a magnetic headprovided with a magnetic sensor incorporating a three-terminal TMRelement 1 of the invention. The magnetic head is provided with thethree-terminal TMR element 1, Au electrodes 61 and a NiFe uppershield/lower core 60 with a thickness of 1 mm on a base 66. Coils 64 andan upper core 65 are further formed thereon. The three-terminal TMRelement 1 serves as a reader while the upper core 65 and the uppershield/lower core 60 serve as a writer. An Al₂O₃ insulating layers 62will prevent an electric leak between the upper magnetic layer and theintermediate magnetic layer of the three-terminal TMR element 1 and anelectric leak between the lower magnetic layer and the intermediatemagnetic layer of the element 1. A NiFe lower shield/electrode 63 isused to form an electrode terminal that is introduced in the lowermagnetic layer of the three-terminal TMR element 1.

[0520]FIG. 230 is a schematic view showing an exemplary structure of amagnetic read/write device of the invention. A spindle motor 93 rotatesa record medium 91 for magnetically recoding information. An actuator 92guides a head slider 90 on a track of the record medium 91.Specifically, in a magnetic disk device, a read head and a write headformed on the head slider 90 will move near a predetermined writingposition on the record medium 91 to sequentially write and read signals.

[0521] Preferably, the actuator 92 is a rotary actuator. The writesignals are written on the medium by the write head via a signalprocessor 94, and the signals are obtained based on an output from theread head via the signal processor 94. For moving the read head on apredetermined recoding track, a highly-sensitive output from the readhead is used to detect the position on the track and the actuator iscontrolled to align the head slider.

[0522] Although only a single head slider 90 and a single recodingmedium 91 are shown in FIG. 230, they may be used in multiple. Therecoding medium 91 may allow writing information on both sides. Wheninformation should be written on both disk faces, the head sliders 90are arranged on both sides of the disk. The magnetic writing device withthe above-described three-terminal TMR element has superiorcharacteristics for coping with a high density than a magnetic writingdevice provided with a conventional magnetic sensor.

[0523] The present invention provides a three-terminal ferromagnetictunnel element whose magnetoresistance has an improved bias voltagecharacteristic due to a bias voltage applied to one of the tunneljunctions. Further, by employing half-metallic ferromagnets in thethree-terminal ferromagnetic tunnel element, enhancement of themagnetoresistance to twice the level of conventional ferromagnetictunnels is stably obtained.

What is claimed is:
 1. A ferromagnetic tunnel magnetoresistive element,comprising: a first ferromagnetic layer; a first insulating barrierlayer formed on the first ferromagnetic layer; a second ferromagneticlayer formed on the first insulating barrier layer; a second insulatingbarrier layer formed on the second ferromagnetic layer; and a thirdferromagnetic layer formed on the second insulating barrier layer,wherein the element further comprises a terminal for applying a firstbias voltage between the first ferromagnetic layer and the thirdferromagnetic layer, and a terminal for applying a second bias voltagebetween the second ferromagnetic layer and the first or thirdferromagnetic layer.
 2. A ferromagnetic tunnel magnetoresistive elementaccording to claim 1, further comprising a first antiferromagnetic layerunder the first ferromagnetic layer for fixing the magnetizationdirection of the first ferromagnetic layer, and a secondantiferromagnetic layer on the third ferromagnetic layer for fixing themagnetization direction of the third ferromagnetic layer.
 3. Aferromagnetic tunnel magnetoresistive element according to either one ofclaims 1 and 2, wherein the second ferromagnetic layer is formed of alamination of three ferromagnetic metal layers.
 4. A ferromagnetictunnel magnetoresistive element according to claim 1, wherein each ofthe first and second ferromagnetic layers is formed of a lamination oftwo ferromagnetic metal layers.
 5. A ferromagnetic tunnelmagnetoresistive element according to any one of claims 1 to 4, whereinat least one of the first, second and third ferromagnetic layers makescontact with a non-magnetic metal layer.
 6. A magnetic head providedwith a magnetoresistive element comprising: a first ferromagnetic layer;a first insulating barrier layer formed on the first ferromagneticlayer; a second ferromagnetic layer formed on the first insulatingbarrier layer; a second insulating barrier layer formed on the secondferromagnetic layer; and a third ferromagnetic layer formed on thesecond insulating barrier layer, wherein the element further comprises aterminal for applying a first bias voltage between the firstferromagnetic layer and the third ferromagnetic layer, and a terminalfor applying a second bias voltage between the second ferromagneticlayer and the first or third ferromagnetic layer.
 7. A magnetic headaccording to claim 6, wherein the element further comprises a firstantiferromagnetic layer under the first ferromagnetic layer for fixingthe magnetization direction of the first ferromagnetic layer, and asecond antiferromagnetic layer on the third ferromagnetic layer forfixing the magnetization direction of the third ferromagnetic layer. 8.A magnetic head according to either one of claims 6 and 7, wherein thesecond ferromagnetic layer is formed of a lamination of threeferromagnetic metal layers.
 9. A magnetic head according to claim 6,wherein each of the first and second ferromagnetic layers is formed of alamination of two ferromagnetic metal layers.
 10. A magnetic headaccording to any one of claims 6 to 9, wherein at least one of thefirst, second and third ferromagnetic layers makes contact with anon-magnetic metal layer.
 11. A ferromagnetic tunnel magnetoresistiveelement, comprising: a first half-metallic ferromagnetic layer; a firstinsulating barrier layer formed on the first half-metallic ferromagneticlayer; a ferromagnetic metal layer formed on the first insulatingbarrier layer; a second insulating barrier layer formed on theferromagnetic metal layer; and a second half-metallic ferromagneticlayer formed on the second insulating barrier layer, wherein the elementfurther comprises a terminal for applying a first bias voltage betweenthe first half-metallic ferromagnetic layer and the second half-metallicferromagnetic layer, and a terminal for applying a second bias voltagebetween the ferromagnetic metal layer and the first or secondhalf-metallic ferromagnetic layer.
 12. A ferromagnetic tunnelmagnetoresistive element according to claim 11, further comprising afirst antiferromagnetic layer under the first half-metallicferromagnetic layer for fixing the magnetization direction of the firsthalf-metallic ferromagnetic layer, and a second antiferromagnetic layeron the second half-metallic ferromagnetic layer for fixing themagnetization direction of the second half-metallic ferromagnetic layer.13. A ferromagnetic tunnel magnetoresistive element according to eitherone of claims 11 and 12, wherein the ferromagnetic metal layer is formedof a lamination of three ferromagnetic metal layers.
 14. A ferromagnetictunnel magnetoresistive element, comprising: a first ferromagnetic metallayer; a first insulating barrier layer formed on the firstferromagnetic metal layer; a half-metallic ferromagnetic layer formed onthe first insulating barrier layer; a second insulating barrier layerformed on the half-metallic ferromagnetic layer; and a secondferromagnetic metal layer formed on the second insulating barrier layer,wherein the element further comprises a terminal for applying a firstbias voltage between the first ferromagnetic metal layer and the secondferromagnetic metal layer, and a terminal for applying a second biasvoltage between the half-metallic ferromagnetic layer and the first orsecond ferromagnetic metal layer.
 15. A ferromagnetic tunnelmagnetoresistive element according to claim 14, wherein each of thefirst and second ferromagnetic metal layers has a lamination of twoferromagnetic metal layers.
 16. A ferromagnetic tunnel magnetoresistiveelement according to claim 14, further comprising a firstantiferromagnetic layer under the first ferromagnetic metal layer forfixing the magnetization direction of the first ferromagnetic metallayer, and a second antiferromagnetic layer on the second ferromagneticmetal layer for fixing the magnetization direction of the secondferromagnetic metal layer.
 17. A ferromagnetic tunnel magnetoresistiveelement according to any one of claims 11 to 16, wherein thehalf-metallic ferromagnetic layer is an oxide or a compound comprisingFe, Co or Mn.
 18. A ferromagnetic tunnel magnetoresistive element,comprising: a first antiferromagnetic layer; a half-metallicferromagnetic layer formed on the first antiferromagnetic layer; a firstinsulating barrier layer formed on the first half-metallic ferromagneticlayer; a first ferromagnetic metal layer formed on the first insulatingbarrier layer; a second insulating barrier layer formed on the firstferromagnetic metal layer; a second ferromagnetic metal layer formed onthe second insulating barrier layer; and a second antiferromagneticlayer formed on the second ferromagnetic metal layer, wherein theelement further comprises a terminal for applying a first bias voltagebetween the half-metallic ferromagnetic layer and the secondferromagnetic metal layer, and a terminal for applying a second biasvoltage between the first ferromagnetic metal layer and thehalf-metallic ferromagnetic layer or the second ferromagnetic metallayer.
 19. A ferromagnetic tunnel magnetoresistive element according toclaim 18, wherein the first ferromagnetic metal layer is formed of alamination of three ferromagnetic metal layers.
 20. A ferromagnetictunnel magnetoresistive element, comprising: a first antiferromagneticlayer; a first ferromagnetic metal layer formed on the firstantiferromagnetic layer; a first insulating barrier layer formed on thefirst ferromagnetic metal layer; a second ferromagnetic metal layerformed on the first insulating barrier layer; a second insulatingbarrier layer formed on the second ferromagnetic metal layer; a thirdferromagnetic metal layer formed on the second insulating barrier layer;and a second antiferromagnetic layer formed on the third ferromagneticmetal layer, wherein the element further comprises a terminal forapplying a first bias voltage between the first ferromagnetic metallayer and the third ferromagnetic metal layer, and a terminal forapplying a second bias voltage between the second ferromagnetic metallayer and the first or third ferromagnetic metal layer.
 21. Aferromagnetic tunnel magnetoresistive element according to any one ofclaims 11 to 20, wherein each of the first and second insulating barrierlayers is made of an oxide or a compound comprising at least one of Al,Mg, Ti, Ta, Hf, Nb, Mo, Cr, Ga and As.
 22. A magnetic head provided witha magnetoresistive element comprising: a first half-metallicferromagnetic layer; a first insulating barrier layer formed on thefirst half-metallic ferromagnetic layer; a ferromagnetic metal layerformed on the first insulating barrier layer; a second insulatingbarrier layer formed on the ferromagnetic metal layer; and a secondhalf-metallic ferromagnetic layer formed on the second insulatingbarrier layer, wherein the element further comprises a terminal forapplying a first bias voltage between the first and second half-metallicferromagnetic layers, and a terminal for applying a second bias voltagebetween the ferromagnetic metal layer and the first or secondhalf-metallic ferromagnetic layer.
 23. A magnetic head according toclaim 22, wherein the element further comprises a firstantiferromagnetic layer under the first half-metallic ferromagneticlayer for fixing the magnetization direction of the first half-metallicferromagnetic layer, and a second antiferromagnetic layer on the secondhalf-metallic ferromagnetic layer for fixing the magnetization directionof the second half-metallic ferromagnetic layer.
 24. A magnetic headaccording to either one of claims 22 and 23, wherein the ferromagneticmetal layer is formed of a lamination of three ferromagnetic metallayers.
 25. A magnetic head provided with a magnetoresistive elementcomprising: a first ferromagnetic metal layer; a first insulatingbarrier layer formed on the first ferromagnetic metal layer; ahalf-metallic ferromagnetic layer formed on the first insulating barrierlayer; a second insulating barrier layer formed on the half-metallicferromagnetic layer; and a second ferromagnetic layer formed on thesecond insulating barrier layer, wherein the element further comprises aterminal for applying a first bias voltage between the firstferromagnetic metal layer and the second ferromagnetic metal layer, anda terminal for applying a second bias voltage between the half-metallicferromagnetic layer and the first or second ferromagnetic metal layer.26. A magnetic head according to claim 25, wherein each of the first andsecond ferromagnetic metal layers is formed of a lamination of twoferromagnetic metal layers.
 27. A magnetic head according to claim 25,wherein the element further comprises a first antiferromagnetic layerunder the first ferromagnetic metal layer for fixing the magnetizationdirection of the first ferromagnetic metal layer, and a secondantiferromagnetic layer on the second ferromagnetic metal layer forfixing the magnetization direction of the second ferromagnetic metallayer.
 28. A magnetic head according to any one of claims 22 to 27,wherein the half-metallic ferromagnetic layer is an oxide or a compoundcomprising Fe, Co or Mn.
 29. A magnetic head provided with amagnetoresistive element comprising: a first antiferromagnetic layer; ahalf-metallic ferromagnetic layer formed on the first antiferromagneticlayer; a first insulating barrier layer formed on the firsthalf-metallic ferromagnetic layer; a first ferromagnetic metal layerformed on the first insulating barrier layer; a second insulatingbarrier layer formed on the first ferromagnetic metal layer; a secondferromagnetic metal layer formed on the second insulating barrier layer;and a second antiferromagnetic layer formed on the second ferromagneticmetal layer, wherein the element further comprises a terminal forapplying a first bias voltage between the half-metallic ferromagneticlayer and the second ferromagnetic metal layer, and a terminal forapplying a second bias voltage between the first ferromagnetic metallayer and the half-metallic ferromagnetic layer or the secondferromagnetic metal layer.
 30. A magnetic head according to claim 29,wherein the first ferromagnetic metal layer is formed of a lamination ofthree ferromagnetic metal layers.
 31. A magnetic head provided with amagnetoresistive element comprising: a first antiferromagnetic layer; afirst ferromagnetic metal layer formed on the first antiferromagneticlayer; a first insulating barrier layer formed on the firstferromagnetic metal layer; a second ferromagnetic metal layer formed onthe first insulating barrier layer; a second insulating barrier layerformed on the second ferromagnetic metal layer; a third ferromagneticmetal layer formed on the second insulating barrier layer; and a secondantiferromagnetic layer formed on the third ferromagnetic metal layer,wherein the element further comprises a terminal for applying a firstbias voltage between the first ferromagnetic metal layer and the thirdferromagnetic metal layer, and a terminal for applying a second biasvoltage between the second ferromagnetic metal layer and the first orthird ferromagnetic metal layer.
 32. A magnetic head according to anyone of claims 22 to 31, wherein each of the first and second insulatingbarrier layers is made of an oxide or a compound comprising at least oneof Al, Mg, Ti, Ta, Hf, Nb, Mo, Cr, Ga and As.